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Isogeometric Topology Optimization Based on Deep Learning

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Communications in Mathematics and Statistics 2022年第3期10卷 543-564页

作者： Taining zheng Xin li School of Mathematical Science University of Science and Technology of ChinaHefeiPeople’s Republic of China

Topology optimization plays an important role in a wide range of engineering applications.In this paper,we propose a novel isogeometric topology optimization algorithm based on deep learning.Unlike the other neural network-based methods,the density distributions in the design domain are represented in the B-spline space.In addition,we use relatively novel technologies,U-Net and DenseNet,to form the neural network structure.The 2D and 3D numerical experiments show that the proposed method has an accuracy rate of over 97%for the final optimization results.After training,the new approach can save time greatly for the new topology optimization compared with traditional solid isotropic material with penalization method and IGA method.The approach can also overcome the checkerboard phenomenon.

关键词： Topology optimization Deep learning Isogeometric analysis B-splines SIMP

Stability Analysis of Networked Evolutionary Games with Profile-Dependent Delays

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Journal of Systems Science & Complexity 2023年第6期36卷 2292-2308页

作者： zheng Yating li Changxi FENG Jun-e School of Statistics and Mathematics Shandong University of Finance and EconomicsJinan250014China Center for Systems and Control College of EngineeringPeking UniversityBeijing100871China School of Mathematics Shandong UniversityJinan250100China

This paper investigates the networked evolutionary games(NEGs)with profile-dependent delays,including modeling and stability analysis.Profile-dependent delay,which varies with the game profiles,slows the information transmission between participants.Firstly,the dynamics model is proposed for the profile-dependent delayed NEG,then the algebraic formulation is established using the algebraic state space approach.Secondly,the dynamic behavior of the game is discussed,involving general stability and evolutionarily stable profile analysis.Necessary and sufficient criteria are derived using the matrices,which can be easily verified by mathematical software.Finally,a numerical example is carried out to demonstrate the validity of the theoretical results.

关键词： Evolutionarily stable profile networked evolutionary games profile-dependent delays semi-tensor product of matrices stability

The Al_(2)O_(3)and Mn/Al_(2)O_(3)sorbents highly utilized in destructive sorption of NF_(3)

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Chinese Journal of Chemical Engineering 2024年第1期65卷 54-62页

作者： Yanfei Pan Hejian li Li Zheng Xiufeng Xu School of Chemistry and Chemical Engineering Yantai UniversityYantai 264005China

NF_(3)is commonly used as an etching and cleaning gas in semiconductor industry,however it is a strongly greenhouse gas.Therefore,the destruction of disposal NF_(3)is an urgent task to migrate the greenhouse effect.Among the technologies for NF_(3)abatement,the destructive sorption of NF_(3)over metal oxides sorbents is an effective way.Thus,the search for a highly reactive and utilized sorbent for NF_(3)destruction is in great demand.In this work,AlOOH supported on carbon-sphere(AlOOH/CS)as precursors were synthesized hydrothermally and heat-treated to prepare the Al_(2)O_(3)sorbents.The influence of AlOOH/CS hydrothermal temperatures on the reactivity of derived Al_(2)O_(3)sorbents for NF_(3)destruction was investigated,and it is shown that the Al2O3 from AlOOH/CS hydro-thermalized at 120℃is superior to others.Subsequently,the optimized Al_(2)O_(3)was covered by Mn(OH)x to prepare Mn/Al_(2)O_(3)sorbents via changing hydrothermal temperatures and Mn loadings.The results show that the Mn/Al_(2)O_(3)sorbents are more utilized than bare Al_(2)O_(3)in NF_(3)destructive sorption due to the promotional effect of Mn_(2)O_(3)as surface layer on the fluorination of Al_(2)O_(3)as substrate,especially the optimal 5%Mn/Al2O3(160℃)exhibits a utilization percentage as high as 90.4%,and remarkably exceeds all the sorbents reported so far.These findings are beneficial to develop more efficient sorbents for the destruction of NF_(3).

关键词： Greenhouse gas NF_(3)destructive sorption Sorbents Al_(2)O_(3) Mn/Al_(2)O_(3) Reactivity

Function-oriented optimization design method for underactuated tendon-driven humanoid prosthetic hand

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Frontiers of Mechanical Engineering 2022年第3期17卷 75-89页

作者： Yue zheng Xiangxin li Lan TIAN Guanglin li CAS Key Laboratory of Human-Machine Intelligence-Synergy Systems Shenzhen Institutes of Advanced Technology(SIAT)Chinese Academy of Sciences(CAS)Shenzhen518055China Shenzhen College of Advanced Technology University of Chinese Academy of SciencesShenzhen518055China SIAT Branch Shenzhen Institute of Artificial Intelligence and Robotics for SocietyShenzhen518055China Guangdong-Hong Kong-Macao Joint Laboratory of Human-Machine Intelligence-Synergy Systems Shenzhen518055China

The loss of hand functions in upper limb amputees severely restricts their mobility in daily life.Wearing a humanoid prosthetic hand would be an effective way of restoring lost hand functions.In a prosthetic hand design,replicating the natural and dexterous grasping functions with a few actuators remains a big challenge.In this study,a function-oriented optimization design(FOD)method is proposed for the design of a tendon-driven humanoid prosthetic hand.An optimization function of different functional conditions of full-phalanx contact,total contact force,and force isotropy was constructed based on the kinetostatic model of a prosthetic finger for the evaluation of grasping performance.Using a genetic algorithm,the optimal geometric parameters of the prosthetic finger could be determined for specific functional requirements.Optimal results reveal that the structure of the prosthetic finger is significantly different when designed for different functional requirements and grasping target sizes.A prosthetic finger was fabricated and tested with grasping experiments.The mean absolute percentage error between the theoretical value and the experimental result is less than 10%,demonstrating that the kinetostatic model of the prosthetic finger is effective and makes the FOD method possible.This study suggests that the FOD method enables the systematic evaluation of grasping performance for prosthetic hands in the design stage,which could improve the design efficiency and help prosthetic hands meet the design requirements.

关键词： function-oriented tendon driven prosthetic hand optimization humanoid underactuated

Vapor growth of V‑doped MoS_(2)monolayers with enhanced B‑exciton emission and broad spectral response

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Frontiers of Optoelectronics 2023年第4期16卷 109-120页

作者： Biyuan zheng Xingxia Sun Weihao zheng Chenguang Zhu Chao Ma Anlian Pan Dong li Shengman li Key Laboratory for Micro-Nano Physics and Technology of Hunan Province State Key Laboratory of Chemo/Biosensing and ChemometricsHunan Institute of Optoelectronic IntegrationCollege of Materials Science and EngineeringHunan UniversityChangsha 410082China College of Advanced Interdisciplinary Studies and Hunan Provincial Key Laboratory of Novel Nano Optoelectronic Information Materials and Devices National University of Defense TechnologyChangsha 410073China Wuhan National Laboratory for Optoelectronics(WNLO) Huazhong University of Science and Technology(HUST)Wuhan 430074China

Dynamically engineering the optical and electrical properties in two-dimensional(2D)materials is of great signifcance for designing the related functions and applications.The introduction of foreign-atoms has previously been proven to be a feasible way to tune the band structure and related properties of 3D materials;however,this approach still remains to be explored in 2D materials.Here,we systematically demonstrate the growth of vanadium-doped molybdenum disulfde(V-doped MoS_(2))monolayers via an alkali metal-assisted chemical vapor deposition method.Scanning transmission electron microscopy demonstrated that V atoms substituted the Mo atoms and became uniformly distributed in the MoS_(2)monolayers.This was also confrmed by Raman and X-ray photoelectron spectroscopy.Power-dependent photoluminescence spectra clearly revealed the enhanced B-exciton emission characteristics in the V-doped MoS_(2)monolayers(with low doping concentration).Most importantly,through temperature-dependent study,we observed efcient valley scattering of the B-exciton,greatly enhancing its emission intensity.Carrier transport experiments indicated that typical p-type conduction gradually arisen and was enhanced with increasing V composition in the V-doped MoS_(2),where a clear n-type behavior transited frst to ambipolar and then to lightly p-type charge carrier transport.In addition,visible to infrared wide-band photodetectors based on V-doped MoS_(2)monolayers(with low doping concentration)were demonstrated.The V-doped MoS_(2)monolayers with distinct B-exciton emission,enhanced p-type conduction and broad spectral response can provide new platforms for probing new physics and ofer novel materials for optoelectronic applications.

关键词： Atomic substitution.V-doped MoS_(2) Distinct B-exciton Broad spectral response

Improving the prognosis of pancreatic cancer:insights from epidemiology,genomic alterations,and therapeutic challenges

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Frontiers of Medicine 2023年第6期17卷 1135-1169页

作者： Zhichen Jiang Xiaohao zheng Min li Mingyang liu State Key Laboratory of Molecular Oncology National Cancer Center/National Clinical Research Center for Cancer/Cancer HospitalChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijing 100021China Department of General Surgery Division of Gastroenterology and PancreasZhejiang Provincial People's HospitalAffiliated People's HospitalHangzhou Medical CollegeHangzhou 310014China Department of Pancreatic and Gastric Surgery National Cancer Center/National Clinical Research Center for Cancer/Cancer HospitalChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijing 100021China Department of General Surgery Beijing Friendship HospitalCapital Medical UniversityBeijing 100050China Department of Medicine The University of Oklahoma Health Sciences CenterOklahoma CityOK 73104USA

Pancreatic cancer,notorious for its late diagnosis and aggressive progression,poses a substantial challenge owing to scarce treatment alternatives.This review endeavors to furnish a holistic insight into pancreatic cancer,encompassing its epidemiology,genomic characterization,risk factors,diagnosis,therapeutic strategies,and treatment resistance mechanisms.We delve into identifying risk factors,including genetic predisposition and environmental exposures,and explore recent research advancements in precursor lesions and molecular subtypes of pancreatic cancer.Additionally,we highlight the development and application of multi-omics approaches in pancreatic cancer research and discuss the latest combinations of pancreatic cancer biomarkers and their efficacy.We also dissect the primary mechanisms underlying treatment resistance in this malignancy,illustrating the latest therapeutic options and advancements in the field.Conclusively,we accentuate the urgent demand for more extensive research to enhance the prognosis for pancreatic cancer patients.

关键词： pancreatic cancer cancer screening single cell molecular alterations precancerous lesion therapy resistance

Ultrasound-guided stellate ganglion blockade: an appealing tactic for cardiac electrical storm

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Journal of Geriatric Cardiology 2023年第5期20卷 376-382页

作者： Zi-Hao LAI li-Hui zheng Yan YAO Arrhythmia Center Fuwai HospitalNational Center for Cardiovascular DiseasesChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijingChina

Ventricular arrhythmia(VA)is a life-threatening cardiac emergency.When VA occurs three times or more within 24 h and interventions are required,it is defined as an electrical storm(ES)characterized by refractoriness and recurrence.[1]For patients with implantable cardioverter defibrillator(ICD),the notion is redefined as no fewer than three appropriate and separate(at least 5 min for each interval)ICD interventions given within 24 h.

关键词： cardiac storm electrical

Model predictive control with input disturbance and guaranteed Lyapunov stability for controller approximation

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Science China(Information Sciences) 2022年第9期65卷 206-218页

作者： Yanye WANG Shaoyuan li Yi zheng Department of Automation Shanghai Jiao Tong University Key Laboratory of System Control and Information Processing Ministry of Education of China

An approximation method that can lower the computational complexity is presented to reduce the processing time of model predictive control(MPC). The effects of the inaccurate inputs, which are caused by the approximation errors, are reflected as input disturbances and are considered in the design of the controller. The closed-loop system’s stability is guaranteed by a restricted Lyapunov-based constraint and input constraints, ensuring that the states will be eventually bounded at a certain confidence level.According to this paper, the effects of the bounded disturbance can be observed via a change in the stability region. The relationship between the regions of the normal and approximated systems is highlighted. The proposed MPC with input disturbance and guaranteed Lyapunov stability is employed in a chemical process,and the simulation results indicate the efficiency of the proposed method.

关键词： model predictive control Lyapunov-based MPC control approximation learning-based control nonlinear system

Exceptional-point-enhanced sensing in an all-fiber bending sensor

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Opto-Electronic Advances 2023年第12期6卷 36-43页

作者： zheng li Jingxu Chen lingzhi li Jiejun Zhang Jianping Yao Guangdong Provincial Key Laboratory of Optical Fiber Sensing and Communications Institute of Photonics TechnologyJinan UniversityGuangzhou 510632China Microwave Photonics Research Laboratory School of Electrical Engineering and Computer ScienceUniversity of OttawaOttawaON K1N 6N5Canada

An exceptional-point(EP)enhanced fiber-optic bending sensor is reported.The sensor is implemented based on paritytime(PT)-symmetry using two coupled Fabry-Perot(FP)resonators consisting of three cascaded fiber Bragg gratings(FBGs)inscribed in an erbium-ytterbium co-doped fiber(EYDF).The EP is achieved by controlling the pumping power to manipulate the gain and loss of the gain and loss FP resonators.Once a bending force is applied to the gain FP resonator to make the operation of the system away from its EP,frequency splitting occurs,and the frequency spacing is a nonlinear function of the bending curvature,with an increased slope near the EP.Thus,by measuring the frequency spacing,the bending information is measured with increased sensitivity.To achieve high-speed and high-resolution interrogation,the optical spectral response of the sensor is converted to the microwave domain by implementing a dual-passband microwave-photonic filter(MPF),with the spacing between the two passbands equal to that of the frequency splitting.The proposed sensor is evaluated experimentally.A curvature sensing range from 0.28 to 2.74 m^(−1) is achieved with an accuracy of 7.56×10^(−4 )m^(−1 )and a sensitivity of 1.32 GHz/m^(−1),which is more than 4 times higher than those reported previously.

关键词： exceptional-point enhanced sensitivity bending sensor parity-time symmetry.